New Hybrid Structures Based on Memanthine and Edaravone Molecules.

New hybrid structures based on memantine and edaravone molecules, in which the pyrazolone ring and adamantane fragments are linked by an alkyl linker, were synthesized. It was found that, in addition to the ability to block the intrachannel site of NMDA receptors, the new hybrid compounds exhibit the property of blockers of the allosteric site of NMDA receptors, which is not inherent in memantine and edaravone preparations. The most active hit compound was determined, which, along with the properties of a two-site blocker of the NMDA receptor, exhibits a pronounced activity as an inhibitor of lipid peroxidation, similarly to the drug edaravone.

Analysis of Immunobiochemical Parameters in Overweight People in Assessing the Risk of Cardiovascular Diseases.

A comparative analysis of specific immunobiochemical parameters, including natural antibodies (NAb) to endogenous regulators of the cardiovascular system, adrenal and gastrointestinal hormones, was performed in students aged 18-22 years with normal and increased body weight (the body mass index from 18.5 to 24.9 kg/m2 and from 25 to 29.9 kg/m2, respectively). The serum content of NAb and hormones was determined by ELISA. The level of the studied indicators depended on the body mass index value. In overweight subjects, the main immune indicators of the biogenic amine system, renin-angiotensin system, and kinin system exceeded the normal. The cortisol level was higher than in subjects with normal body weight. Aldosterone secretion was less dependent on the ACTH content and was lower than in students with normal body weight. The content of cholecystokinin and gastrin corresponded to the values for overweight. These trends in hormone contents are a predisposing factor for further weight gain. Practical significance of the combined assessment of disturbances in the immunological and biochemical homeostasis has been established. Analysis of the adrenal and gastrointestinal hormones can predict the risk of weight gain, but at the same time, changes in the level of immunological indicators in subjects with increased body weight characterizes the possibility of developing cardiovascular pathologies.

Measurement of Immunological Parameters to Assess Human Body Readiness for Physical Load.

We measured the level of natural antibodies (nAb) to glutamate and GABA reflecting the balance of excitation and inhibition systems and involved in the adaptation processes in athletes receiving normalized physical activity in the dynamics of training (figure skaters, football players, and people actively involved in sports). It was found that each subject has an individual immunological profile and its parameters change in accordance with the training load. The measured levels of nAbs to GABA and glutamate correlate the physical activity of a person. The surveyed football players were divided into 3 groups according to the results of the analysis. Subjects of the first group had reliably high immunological indices in comparison with the control and were at the peak of physical form; in the third group, low immunological indices relative to the control indicated exhaustion and fatigue. The indicators of the second group corresponded to normal and demonstrated the resource of adaptation to load. The developed method can be used for assessing person's readiness for physical activity.

Role of Potassium Ions in Regulation of Calcium-Activated Chloride Channels.

Using the patch-clamp method in the whole cell configuration, it was shown that external potassium ions play an important role in the regulation of calcium-activated chloride channels (CaCCs). A clear dependence of the conductivity of the СаССs on the external potassium concentration was shown. The effect of external potassium in the range 0-15 mM on the conductivity of chloride channels was significantly greater than the effect it had on other ionic currents (sodium or potassium). There is reason to believe that these changes in the conductivity of CaCCs may contribute to the development of pathophysiological processes such as hypokalemia or hyperkalemia.

Modulation of Calcium-Activated Chloride Currents in Rat Neurons with New 2-Aminotiophene-3-Carboxylic Acid Derivatives.

Using the patch-clamp method in the whole cell configuration, it was shown that new conjugates of 2-aminothiophene-3-carboxylic acid with adamantane derivatives exhibit the ability to modulate CaCC activity in the single Purkinje neurons of rat cerebellum. It was noted that, depending on the nature of the substitution in the thiophene fragment, the nature of the effect on CaCC varies from inhibition to potentiation of CaCC currents. The described compounds are also blockers of the NMDA receptor ifenprodile site, which may have an additional neuroprotective contribution to the spectrum of biological activity of these compounds.

The Effect of Ionizing Radiation on Cognitive Functions in Mouse Models of Alzheimer's Disease.

The present study demonstrates the effect of combined ionizing radiation (γ rays, 0.24 Gy, 661.7 keV, whole body and 12C, 0.18 Gy, 450 MeV, head region) on the behavior of animals in mouse transgenic models of Alzheimer's disease. Significant improvement of spatial learning and stimulation of locomotor and exploratory behavior were observed in wild-type mice after irradiation. However, an anxiolytic effect and stimulation of locomotor and exploratory behavior were revealed in irradiated mice with tauopathy. Mice with cerebral amyloidosis also exhibited improved learning in the odor recognition test. No negative effects of irradiation were detected.

Wave-Like Dose-Dependence of the Stimulating Effects of Dimebon on Cognition in a Wide Dose Range.

Comparison of the cognition-stimulating effects of Dimebon in a wide dose range revealed a non-monotonic and nontrivial wave-like dose-dependence of its activity. Positive results were obtained at low (0.02-0.05 mg/kg) or high (5-10 mg/kg) doses of Dimebon, while intermediate doses were ineffective. This type of the dose dependence of the pharmacological effect can indicate that the substance has several targets. This fact should be taken into consideration when selecting the doses and concentrations of the substance and its analogues for further studies, and for planning treatment schemes and administration doses in clinical studies.

New Positive Allosteric Modulator of AMPA Receptors: in vitro and in vivo Studies.

A new derivative of 3,7-diazabicyclo[3.3.1]nonane, which showed a high activity as a positive allosteric modulator of AMPA receptors of the CNS, was studied in electrophysiological experiments. At doses of 0.01 mg/kg, this compound significantly improved the memory of experimental animals disturbed by maximal electric shock. The results indicate that this compound is a promising candidate for preclinical trials and clinical studies as a drug for treatment of a number of psychoneurological diseases.

Synuclein Deficiency Decreases the Efficiency of Dopamine Uptake by Synaptic Vesicles.

In the present study, we analyzed the uptake of radiolabeled dopamine by intact synaptosomes and purified synaptic vesicles isolated from the dorsal striatum of mice with constitutive inactivation of all three synuclein-coding genes and wild-type mice. Synuclein deficiency substantially compromised the uptake of this neurotransmitter by synaptic vesicles but had no effect on synaptosomal dopamine uptake.

Anticholinesterase and Antioxidant Activity of New Binary Conjugates of γ-Carbolines.

The synthesized new binary conjugates of tetrahydro-γ-carbolines, which contained ditriazole spacers of different length, exhibited considerable anticholinesterase and antioxidant activity as well as the potential ability to block the acetylcholinesterase-induced aggregation of ß-amyloid in contrast to the original prototype Dimebon. This makes the compounds promising candidates for further investigation as drugs for the treatment of Alzheimer's disease. Special attention should be given to the conjugate containing the hexamethylene intertriazole spacer, which can be considered as a leader in this series of compounds.

[Dimebon correction of changes in phospholipid composition induced by tumor necrosis factor-alpha in experement]. / Korrektsiia dimebonom narushenii sostava fosfolipidov v strukturakh mozga, vyzvannykh faktorom nekroza opukholi α v éksperimente.

AIM: To investigate the ability of the neuroprotector dimebon to prevent alterations in brain lipid metabolism caused byTNF-α. MATERIAL AND METHODS: The ability of dimebon (2,8-Dimethyl-5-[2-(6-methyl-3-pyridinyl)ethyl]-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole hydrochloride) to prevent alterations in brain lipid metabolism caused byTNF-α was studied in 65 male mice (20+2g weight). TNF-α (10 mkg/mouse), dimebon (0.2 mg/kg) and their combination were injected intraperitoneally. Thirty min, 2, 4 and 24 h after injection, lipid level alterations in total fractions and molecular species of phospholipids (phosphatidylcholine, lysophosphatidylcholine, sphingomyelin and phosphatidylethanolamine) were measured with mass-spectrometry in the hippocampus, cortex and cerebellum. RESULTS AND CONCLUSION: After injection of TNF-α into mice, there are significant changes in the level of all tested phospholipids. Dimebon at a dose of 0.2 mg/kg alone does not cause any changes in the content of all tested phospholipids, but injected together with TNF-α prevents cytokine induced alterations in the lipid content. The selectivity of TNF-α and dimebon influence on certain molecular species of various phospholipids in different parts of mouse brain is found. The presented data suggest protective properties of dimebon preventing the development of proinflammatory syndrome induced by TNF-α in the animal brain.

Influence of Al3+, Fe3+ and Zn2+ Ions on Phosphorylation of Tubulin and Microtubulo-Associated Proteins of Rat Brain.

Phosphorylation of τ-protein, a component of microtubules in brain neurons, is a key pathomorphological sign of Alzheimer's disease. The development of this intracellular defect can be promoted by Al3+, Fe3+, and Zn2+ ions. The concentrations of these ions in the brain are considerably elevated in Alzheimer's disease. We performed a comparative study of phosphorylation of microtubular proteins of rat brain in the presence of Al3+, Fe3+, and Zn2+ ions in concentrations of 10-500 µM and microtubular proteins of brain of patients with Alzheimer's disease. The most likely candidate for the role of a factor that promotes hyperphosphorylation of τ-protein is Al3+ in concentrations of 250 and 500 µM.

Gamma-Carbolines Derivatives As Promising Agents for the Development of Pathogenic Therapy for Proteinopathy.

Uncontrolled protein aggregation, accompanied by the formation of specific inclusions, is a major component of the pathogenesis of many common neurodegenerative diseases known as proteinopathies. The intermediate products of this aggregation are toxic to neurons and may be lethal. The development strategy of pathogenic therapy for proteinopathy is based on the design of drugs capable of both inhibiting proteinopathy progression and increasing the survival of affected neurons. The results of a decade-long research effort at leading Russian and international laboratories have demonstrated that Dimebon (Latrepirdine), as well as a number of its derivatives from a gamma-carboline group, show a strong neuroprotective effect and can modulate the course of a neurodegenerative process in both in vitro and in vivo model systems. The accumulated data indicate that gamma-carbolines are promising compounds for the development of pathogenic therapy for proteinopathies.

Effect of New Derivatives of 2-Aminothiophene-3-Carboxylic Acid on Calcium-Activated Chloride Currents in Rat Neurons.

Using the patch-clamp method in the whole-cell configuration, we showed that the new derivatives of 2-aminothiophene-3-carboxylic acid, which were synthesized by us earlier, can both block (compound 1) and potentiate (compound 2) calcium-activated chloride currents in single rat cerebellar Purkinje cells.

Conjugates of Tacrine and Its Cyclic Homologues with p-Toluenesulfonamide as Novel Acetylcholinesterase and Butyrylcholinesterase Inhibitors.

Using the acylation reaction with tosyl chloride of N-aminopropyl analogues of tacrine and its cyclic homologues with different size of the aliphatic cycle (5-8), we synthesized a number of new derivatives of p-toluenesulfonamide. It is shown that the synthesized hybrid compounds of tacrine and p-toluenesulfonamide are effective inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with the preferential inhibition of BChE. They also displace propidium from the peripheral anionic site of the electric eel AChE (Electrophorus electricus). The characteristics of the efficiency and selectivity of cholinesterase inhibition by the test compounds were confirmed by the results of molecular docking.

Enzyme Immunoassay of Antibodies to Endogenous Bioregulators for Evaluating the Risk of Heart Disease.

The levels of natural antibodies to ß-endorphin, bradykinin, histamine, dopamine, and serotonin were measured in 271 cardiological patients in order to evaluate the severity of their clinical status. The patients were distributed into groups differing by the course of the pathological process. The levels of natural antibodies to all antigens were maximum in patients with cardiosclerosis: the content of antibodies to ß-endorphin surpassed the control by 46%, to histamine by 62%, to bradykinin by 36%, to dopamine by 49%, and to serotonin by 65%.

[Dimebon delays the onset of symptoms of FUS-proteinopathy in transgenic mice]. / Otsrochennyi debiut simptomaticheskoi stadii FUS-proteinopatii u transgennykh myshei pod deistviem dimebona.

AIM: To evaluate an effect of dimebon on the onset of symptomatic stage in FUS.1-513 transgenic mice - a new genetic model of neurodegeneration, and to study the dynamics of disease progression in the terminal stage. MATERIAL AND METHODS: The study was carried out on males of line FUS1-513 with the contribution of genes from CD1 strains. Mice of the experimental group (n=28) received dimebon with water in the concentration of 70 mcg/ml starting from the 35th day of life. The control group (n=25) did not receive the drug. Age, body mass of animals at the start of symptomatic stage and duration of symptomatic stage were assessed. RESULTS: Application of dimebon can delay the onset of the manifestation of clinical symptoms of the neurodegenerative process in the experimental group (127.6±4.6 days) compared to the control group (110.6±4.2 days). The body mass was similar in both groups. CONCLUSION: Dimebon leads to an increase in the duration of presymptomatic stage and delays the manifestation of clinical symptoms. The changes in the dynamics of the pathological process in the symptomatic stage are not detected.

Novel conjugates of tacrine with 1,2,4,-thiadiazole as highly effective cholinesterase inhibitors, blockers of NMDA receptors, and antioxidants.

Conjugates of tacrine with 1,2,4-thiadiazole derivatives were synthesized for the first time. Their esterase profile and effects on the key NMDA receptor-binding sites as well as antioxidant activity were investigated. The obtained compounds effectively inhibited cholinesterases (with a predominant effect on butyrylcholinesterase), simultaneously blocked two NMDA receptor-binding sites (allosteric and intrachannel sites, and exhibited a high radical-scavenging activity. Our study shows that the obtained compounds are promising to design drugs for the treatment of Alzheimer's disease and other multifactorial neurodegenerative diseases.

Tetraethylammonium and 4-aminopyridine block calcium-dependent chloride current in rat cerebellum Purkinje cells.

Using patch-clamp method (whole cell configuration), it was shown that tetraethylammonium (TEA) and 4-aminopyridine (4-AP) block calcium-dependent chloride currents in the membrane of freshly isolated cerebellar Purkinje cells of rats (12-15 days). In the concentration range studied (50 µM-10 mM TEA and 100 µM-1 mM 4-AP), both compounds blocked the chloride current at IC50 130 µM for TEA and 110 µM for 4-AP. TEA blockade was reversible after washing. The effect of 4-AP at concentrations greater than 100 µM was irreversible: both outward and inward chloride currents were blocked even after the removal of 4-AP from the incubation medium.

Pro-Cognitive Effects of Non-Peptide Analogues of Soluble Amyloid Peptide Precursor Fragment sAPP.

We studied pro-cognitive effect of two heterocyclic low-molecular-weight compounds that serve as non-peptide analogues of soluble fragment of amyloid peptide precursor (sAPP). Intracerebroventricular and systemic administration of peptide mimetics P2 and P5 improved weak memory on the model of passive avoidance in chicks and in the object location task in mice. Both compounds were effective if administered close to the moment of training or 4 h after it. The time windows and dose range for the pro-cognitive effects of the mimetics were similar to those observed in previous studies with sAPP peptide fragments.